1. Field of the Invention
This invention relates to a reflection type scanner to transparence type scanner converter, especially to a converter enabling a reflective image scanner to be used as a transparence type image scanner.
2. Description of the Prior Art
The image scanner is a useful input device for the computer system to input images into it. Conventional scanners are separated into two groups: the reflection type scanners and the transparence type scanners. FIG. 1 is a light path diagram of a standard reflection type hand-held scanner. The diagram also shows the general structure of a reflection type scanner in which 1 is a lamp, 2 is a reflecting mirror, 3 is a lens, 4 is an image sensor (such as a charge coupled device, CCD), and 5 is a casing.
The light emitted by the lamp 1 is directed toward the document D placed on the platform, and then reflected off the reflecting mirror 2 to the lens 3. After undergoing idiotic image formation, the light enters the light sensor 4. Since the image component of the document is loaded onto the light during reflection, the image sensor can convert the image component into electrical voltage for input to a computer system (not shown) for processing.
FIG. 2 is a light path diagram of a standard transparence type hand-held scanner. The diagram shows the general structure of the transparence type scanner. Those members of the diagram also appearing in FIG. 1 are labeled with the same numbers. As can be seen in the diagram, the light emitted by the lamp 1 passes through a collimator 6 to the document D. The document D is translucent (typically plastic image recording media, such as negatives or slides). Light from the lamp 1 that reaches the document D passes through the document D and picks up the image component of the document D. The light then continues on to the reflecting mirror 2 to be reflected to the lens 3, and then after undergoing idiotic image formation, enters the image sensor 4. The image sensor 4 then converts the image component of the document D into electricity to be input to the computer system (not shown) for processing.
Transparence type and reflection type scanners are different in structure and are used with image recording media of differing natures. Reflection type scanners are typically suited to media with relatively high reflectivity, such as paper, film, etc. Transparence type scanners, on the other hand, are suited for use with media made from materials with relatively high transparence, such as the above-mentioned negatives and slides, or projection film. Users who require the use of both types of media thus have to purchase two types of scanners. Users, however, for reasons of utility and economics, prefer not having to purchase one each of the above-mentioned types of scanners when different media materials have to be scanned.
Thus the provision of a dual-function reflection-transparence scanner has become a matter of concern in the industry. Also, the recording media suited for use with transparence type scanners typically has special specifications and is made of special materials, which makes manufacture of these devices relatively complex. Simplification of these devices is thus a current task of the industry.
It is thus an object of the present invention to provide a reflection-transparence scanner converter which can endow a reflection type scanner with transparence type scanner capabilities.
Another object of the present invention is to provide a scanner that combines the functions of reflection and transparence type scanning.
Another object of the present invention is to provide a simplified transparence type scanner.